Field of the Invention
The present invention relates generally to stereoscopic displays and, more specifically, to cut-away stereo content in a stereoscopic display.
Description of the Related Art
Digitally displayed technology has advanced to the point where content can be readily displayed stereoscopically to the viewer. Such display technology exists not only for large-scale projection systems, as in movie theaters, but also for computer and television displays as well. Stereoscopic display technology, used in conjunction with suitably configured stereoscopic viewing eyeglasses, allows a viewer to view content on a computer or television in what appears to be three dimensions (3D), either for an enhanced viewing experience or to better facilitate viewer interaction with an application that presents content in 3D.
Direct touch interaction with 3D content can greatly facilitate some operations, particularly in 3D modeling. For example, in a stereoscopic display region, hand gestures may be more effective than 2D cursor-based commands for manipulating 3D content that presented to appear in the display region. Selection of objects (e.g., by pinching), gross positioning of objects in three dimensions (e.g., by pinching and dragging), and rotation of objects (e.g., by swiping) can all be performed more quickly and ergonomically than by employing cursor-based or keyboard-based commands.
In some situations, though, direct touch interaction with stereoscopically displayed content, such as software widgets or other tools, can be problematic. For example, whenever a physical object, such as a user's hand, occludes displayed 3D content that is rendered to appear in front of the physical object, discrepancies in depth cues can occur. Stereoscopic display relies on the depth cues referred to as “convergence” and “accommodation” to inform a user's depth perception, so that the apparent location of the occluded 3D content appears closer to the user than the physical object appears to the user. Therefore, the occluded 3D content should appear to occlude the physical object. However, the physical object is still visible to the user, even though the displayed content, based on convergence and accommodation cues, should block the line of sight between the user and the physical object. This contradictory visual information breaks the illusion created by stereoscopic display. Worse, significant visual discomfort may result, including double vision, headache, and even nausea.
As the foregoing illustrates, there is a need for ways to display content stereoscopically that maintain proper 3D illusions created through stereoscopic display and do not cause visual discomfort during direct touch interactions.